National Repository of Grey Literature 50 records found  1 - 10nextend  jump to record: Search took 0.00 seconds. 
Výskyt a diverzita amphistomních motolic u skotu
VOGALOVÁ, Pavlína
The thesis deals with gastric woodlice of the family Paramphistomidae, which are common parasites of ruminants. Their immature stages can cause severe pathological changes in the host's digestive tract, and massive infection can lead to host death. Adult parasites cause infections of the rumen mucosa, resulting in lower production. The prevalence and diversity of these flukes is currently not systematically monitored. The aim of this study is to describe the occurrence and diversity of gastric flukes in cattle in the Czech Republic and Austria. The practical part consists of examination of dairy cattle faeces from different herds for the presence of eggs using standardised parasitological methods, optimization of a PCR method for direct detection of flukes from the faeces, genotyping of the flukes found, processing of the results using appropriate statistical methods, and comparison with published data.
Životní cyklus motolice \kur{Anomalotrema koiae} Gibson & Bray, 1984 (Digenea: Opecoelidae) na souostroví Svalbard
NOVOTNÝ, David
The aim of the study is to describe the life cycle of a trematode species Anomalotrema koiae Gibson & Bray, 1984 (Digenea: Opecoelidae) which occures in three species of whelks (Buccinum undatum, B. glaciale and Plicifusus kroyeri) and Arctic staghorn sculpin (Gymnocanthus tricuspis) in littoral waters, mainly fjords, of the Svalbard archipelago to better understand the ecology of arctic marine habitats. In the study there is the first morphological description of larval stages of A. koiae, mainly the sporocysts and cercariae. For the purpose of the study, there were used both the molecular and morphological methods to analyse the data from the samples which were collected on Svalbard.
Motolice nadčeledi Hemiuroidea v rybách a ploutvenkách na Svalbardu
BRANIŠOVÁ, Vendula
The aim of this study was to obtain information about diversity of trematodes of the superfamily Hemiuroidea of fishes, chaetognaths and molluscs in Svalbard and thus contribute to the knowledge of the life cycles of these trematodes. This work used molecular and morphological methods to identify adult and larval stages of trematodes.
The role of humoral factors in the snail immune response against schistosomes
Košťáková, Monika ; Horák, Petr (advisor) ; Dvořák, Jiří (referee)
Digenetic trematodes such as Schistosoma mansoni use molluscs, mainly Gastropoda in their life cycle, as their intermediary hosts. e internal defense system (IDS) of snails is composed of immune cells called hemocytes, which are the main effectors and act jointly with soluble components. Humoral factors could in uence directly the parasite's larval stage, the activity of hemocytes and also may serve in recognition of the parasite. Lectins are considered to be the main component of humoral immunity. ey have a primary role in non-self recognition. Other protein group with lectin-like activity called FRePs was found in Biomphalaria glabrata. eir unique structure contains a brinogen and an immunoglobulin-like domain. Cytokine-like molecules may play very important role in defense as well. Many molecules are present in hemolymph and their levels change during infection. e response to parasitosis is therefore very complex and still awaits further clari cation.
Inhibitors of proteolytic enzymes of Trematodes
Šteiger, Vladimír ; Kašný, Martin (advisor) ; Salát, Jiří (referee)
i Abstract Trematodes are important parasites possessing various localization in the bodies of invertebrate and vertebrate hosts, including human; therefore they are subject of long time intensive worldwide research. Trematodes developed various adaptations and strategies (some of them have also molecular background) enable them to survive in the host bodies. Trematodes produce large amount of different molecules, which are involved in various physiological processes. Inhibitors of proteolytic enzymes form a large group of biologically active compounds, e.g. they regulate the activity of peptidases or modulate host immune response. Many of these inhibitors are investigated as potential candidates in chemotherapeutic fight against trematodes. This thesis reviews the information concerning the natural inhibitors produced by trematodes and also synthetic inhibitors. Key words: Inhibitor, trematode, peptidase, serpin, cystatin i
Production and elimination of superoxide radical in relation to the compatibility of snails and trematodes
Cibulková, Lucie ; Skála, Vladimír (advisor) ; Nývltová, Eva (referee)
Almost all trematodes use snails as the intermediate host in their life cycles. To survive within the host, they have to efficiently avoid defense reactions of its immune system. The most important effector cells, haemocytes, produce reactive oxygen species with the first molecule known as superoxide radical. Various snail species produce different levels of these radicals in relation to the compatibility with the invasive trematode species. The parasite decreases the levels of toxic radicals by using antioxidant enzymes including superoxide dismutase which catalyzes transformation of superoxide radical into hydrogen peroxide. This dismutation reaction is the first step during the oxidative burst and likely influences survival of trematodes within the host. Based on the current knowledge the production and elimination of superoxide radical in relation to the compatibility between snails and trematodes have been described thoroughly for a few models such as for example Biomphalaria glabrata-Schistosoma mansoni. However, this interaction appears to play a key role and, therefore, it deserves more attention in another models as well. Key words: trematodes, snails, compatibility, haemocytes, oxidative burst, antioxidant enzymes, superoxide dismutase, superoxide radical
Glycocalyx shedding by cercariae of bird schistosomes
Chaloupecká, Jana ; Mikeš, Libor (advisor) ; Štěrba, Ján (referee)
Trichobilharzia spp. are avian schistosomes related to medically important human parasites of the genus Schistosoma. Penetrating cercariae are well known as causative agent of cercarial dermatitis in humans. Cercariae actively penetrate the skin of definitive hosts and transform into schistosomula. This process is preceded by cercarial tail detachment and includes emptying of penetration glands and extensive surface changes. One of these changes is the loss of highly immunogenic glycocalyx which represents a protective coat in the aquatic environment. The glycocalyx has specific composition of saccharide molecules which are bound to lipids or proteins on the membrane of cercarial tegument. There is only limited information about the mechanism of shedding. Hypotheses based on indirect evidences suggest that peptidases or (phospho)lipases from penetration glands could be involved. This work describes the changes in surface glycosylation during transformation of cercariae into schistosomula by fluorescently labelled lectins and monoclonal antibodies against Lewis X antigen. Lectins UEA-I, LTA and PNA have been chosen as markers of transformation of T. regenti. Further, our experiments have been focused on shedding of cercarial glycocalyx. During in vitro induction of penetration gland emptying and...
Features and functions of glycocalyx of trematode cercariae
Chaloupecká, Jana ; Mikeš, Libor (advisor) ; Kašný, Martin (referee)
Trematodes are parasites from phylum Platyhelminthes which have compex life cycles involving two to four hosts. This work focuses especially on trematodes of the family Schistosomatidae. Their cercariae which leave the snail intermediate host, actively penetrate the skin of definitive hosts and transform into schistosomula. This is accompanied by detachment of cercarial tail and emptying of penetration glands. During transformation, cercarial bodies undergo extensive ultrastructural and molecular changes. One of these changes is the loss of surface glycocalyx which represents a protective coat in the aquatic environment. In glycocalyx shedding, participation of proteolytic enzymes from cercarial penetration glands is expected during invasion of the host. Glycocalyx has specific composition of saccharide molecules which are bound to lipids or proteins on the membrane of cercarial tegument. This work describes the origin, ultrastructure, saccharide composition, function and shedding mechanism of cercarial glycocalyx.
Larval Stages of Flukes (Platyhelmintes: Trematoda) in Secondary School Education
Šulcová, Hana ; Říhová, Dagmar (advisor) ; Podroužková, Štěpánka (referee)
The parasites are one of the most important factors that shape relationships in the nature. This thesis deals mainly with developmental stages of trematodes (Platyhelmintes: Trematoda), especially the cercariae of so-called Schistosomes and sporocysts of Leucochloridium paradoxum, as well as with and their intermediate host - freshwater snails. Introductory chapters are focused on general introduction into the topic, such as basic terminology or occurrence issue of trematodes (mainly schistosomes) in the world and in the Czech Republic. In order to determine larval stages of flukes and their morphological types, the research was conducted in four Prague localities with known presence of aquatic snails. Only in one site, Kunratická tůň Pond, the constant presence of echinostomous cercariae (and in lesser extent also furcocercariae) in Radix labiata was recorded during summer season of 2015. In small pond in the Botanical Garden of the Natural Sciences Faculty of Charles University and in Modřanské tůně Ponds, xiphidocercarie in Lymnaea stagnalis were found. No cercarie were detected in the pond in the Genetic garden of Charles University. The presence of Leucochloridium paradoxum in the European Amber Snail Succinea putris was confirmed in the vicinity of Modřanské tůně Ponds. The verified...
Ontogenesis of trematode larval stages of the family Fasciolidae in the intermediate snail hosts.
Pankrác, Jan ; Kašný, Martin (advisor) ; Soldánová, Miroslava (referee)
The family Fasciolidae is an important group of trematodes including serious pathogens of humans and livestock. The life cycle is divided into two phases - sexual reproduction in the definitive host body (large land mammals) and an asexual reproduction in the intermediate host body (aquatic snails of the family Lymnaeidae and Planorbidae). Development within the snail host is characterized by production of large amounts of parasite larvae (sporocyst, rediae, cercariae). Cercariae released from the snail immediately start to transform into metacercariae, the larval stages infectious for definitive host. Snail phase of infection is generally accompanied by number of mostly negative symptoms (massive pathological changes, often followed by reduction of fertility). This summary reveals that current knowledge concerning the ontogenetic development of fasciolids in the intermediate host is uncomplete and unequally investigated. According to this summary is also obvious that some of the published findings are universally valid for all members of the family Fasciolidae and other are characteristic only for particular species.

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